Generally described, gas turbine engines include a compressor to compress an incoming flow of air for combustion with a compressed flow of fuel in a combustor. The compressor includes a number of progressively higher pressure stages. Each stage includes a row of rotor blades mounted on a rotor and a number of stator vanes mounted on a casing. The compressor also may use a number of variable stator vanes. The variable stator vanes generally extend between adjacent rotor blades. The variable stator vanes are rotatable about an axis so as to direct the airflow through the compressor. The variable stator vanes thus may control the quantity of air flowing through the compressor so as to facilitate optimized performance. The size and configuration of the variable stator vanes may vary.
Control of the angle of the variable stator vanes thus is required so as to provide this optimized performance. Mechanical interference or clashing of rotor blades and the variable stator vanes, however, may result if the variable stator vanes extend too far open or closed. Such mechanical inference or clashing may result in component damage. Moreover, significant downtime thus may result from such clashing and may require extensive repair.
There is thus a desire therefore for improved variable stator vane control systems. Such improved control systems should avoid mechanical interference between the variable stator vanes and rotor blades while providing optimized airflow for overall system efficiency and output.